The loss of refrigerant such as R-12 refrigerant from refrigeration systems, particularly during servicing of automotive air conditioning systems is the subject of much public concern at this time. A refrigeration service mechanic in servicing the air conditioning system normally vents the same. During venting, a significant amount of R-12 vapor is lost from the air conditioning system. There is a need, therefore, to provide a practical, simple, effective and low cost refrigerant recovery and restoration system which will allow the mechanic to vent an automotive air conditioning system with full recovery of the vapor contained therein, to provide a system which at least in part is relatively transportable to the situs of the automotive or like air conditioning or refrigeration system, which produces reclaimed refrigerant of equal quality in comparison to virgin refrigerant, which is small in size, but which will be capable of operating with the volume of normal automotive air conditioning service operation.
Attempts have been made to produce an effective refrigerant recovery and/or disposal, purification and recharging system. Issues U.S. Patents representative of such known systems are:
U.S. Pat. No. 3,232,070; PA0 U.S. Pat. No. 4,285,206; PA0 U.S. Pat. No. 4,363,222; PA0 U.S. Pat. No. 4,441,330; PA0 U.S. Pat. No. 4,476,688; PA0 U.S. Pat. No. 4,539,817; PA0 U.S. Pat. No. 4,554,792; PA0 U.S. Pat. No. 4,646,527; and PA0 U.S. Pat. No. 4,766,733.
These Patents disclose as aspects of such refrigerant recovery systems the employment of components such as compressors, vacuum pumps, oil separators, condensers, liquid refrigerant receivers and accumulators. Unfortunately, the systems identified above are characterized by relatively low reclaimed refrigerant quality, compared to virgin refrigerant, by complexity and high pressure operation and are plagued with maintenance problems due particularly to the high pressure portions of the system and the need for periodic replacement of filters and desiccants.
It is therefore an object of the present invention to provide an improved, low cost, simple, essentially atmospheric pressure operated refrigerant recovery and restoration system which operates primarily as a direct condensation process, which has particular application to servicing automotive air conditioning systems, but is not limited thereto, and which may be advantageously employed in servicing home refrigerators or systems using R-12 as refrigerant, and which obviates the problems discussed above with respect to the known prior art.